Heavy atom–surface scattering at hyperthermal energies

We have measured energy- and angle-resolved scattered spectra for 10–250 eV Rb+ ions incident on a Cu(001) surface at angles of 45° and 65° with respect to the surface normal. These spectra indicate that the scattering for this heavy atom–surface system involves multiple collisions with surface atoms that are binary in nature. Using a classical trajectory simulation, the trajectories that lead to scattering are analyzed and are shown to be similar to results obtained in light atom–surface systems. Based on the simulation results, a new trajectory type is proposed that involves the rehitting of a scattered Rb+ ion by a recoiling surface atom.